Best Weapons/Spells/Techniques

Here is a list of some memorable stuff that I can remember:

Duke Nukem 3d: Shrink Ray! Hilarious weapon where you shrunk an enemy and then stepped on him.

Command & Conquer: Ion Cannon. Instantly memorable at the time, an awesome weapon to use.

C&C Red Alert: Tesla Coil. The pinnacle of defensive structures in RTS games. It made this overexaggerated zapping sound that just kicked ass.

Heroes of Might & Magic 2: Chain Lightning. It was the first time I had seen the spell reinacted so perfectly, and it has been imitated countless times now.

StarCraft: Siege Tank. Infamous unit that truly solidified SC as an innovator of the RTS genre. The fact that C&C Tiberian Sun's Artillery unit was a blatant ripoff only helps emphasize this point.

Ratchet & Clank: RYNO. Outrageous, and overglorified destructive power tucked into one weapon.

Diablo 2: Auras. The idea seems second nature in many games now, but I cannot recall any game ever using them before Diablo 2.

Diablo 2: Corpse explosion. The coolest looking spell in the game. Get a powerful necro, hop into the cow level and this baby becomes your best friend.

X-men V SF: Royal Flush, Gambit's hypercombo. Overexaggerated and fun to watch, exactly what a "super" should be.

Twisted Metal 2: Mr. Slam's special. His crane grabs your car, and tosses it like a ragdoll.

Jam it back in, in the dark.